The US Securities and Exchange Commission has issued a stern statement in regard to potentially unlawful online trading platforms. The statement includes a warning to investors that they should use "SEC-registered and regulated marketplaces" for virtual currency (VC) trading. The value of Bitcoin, and other VCs, dipped dramatically after the statement's publication.
https://www.notebookcheck.net/Bitcoin-value-damaged-by-SEC-statement.287620.0.html